This invention relates generally to vacuum tools and, more particularly, to vacuum grips for controllably gripping and releasing movable objects.
One key to a successful and economical manufacturing operation is the intelligent use of automatic manufacturing methods. Many automated manufacturing operations require that a part, subassembly or finished product be physically moved from one location to another. To do this automatically requires the ability to grip an object, convey it precisely to a new location and thereafter release the object at that location. Various methods and mechanisms have evolved for achieving this goal.
One preferred approach, commonly used in handling small and delicate electronic components in the manufacture of electronic devices and circuitry, is the use of a partial vacuum to grip the objects or articles to be moved. Vacuum gripping is advantageous in that it minimizes the physical stress placed on the conveyed object, avoids marring or otherwise affecting the appearance of the conveyed object, and is conveniently controlled to permit quick and easy release of the conveyed object. Various types of vacuum gripping devices are shown, for example, in the following U.S. Patents:
______________________________________ Patent No. Title Inventor ______________________________________ 5,169,192 Electronic Article Pickup Tool Allison, et al. 5,308,132 Circuit Assembly Device for Kirby, Programmably Controlling et al. Placement Force and Method Thereto 4,995,662 Suction Pickup Apparatus for Electrical or Electronic Components Hawkswell 4,796,357 Method and Apparatus for Positioning Electrical Components Smith 4,763,941 Automatic Vacuum Gripper Sniderman 3,804,397 Automatic Positioning Vacuum Cup Newmann 2,934,086 Vacuumatic Valve Blatt ______________________________________
These devices generally rely on external vacuum pumps to create a partial vacuum that is controllably valved through, or blocked by, the device to grip and release the object to be conveyed. Although effective, the need for an external vacuum source in addition to external control circuitry or linkages adds to the complexity and cost of the overall system, provides another area for potential system malfunction and further complicates overall system maintenance. A need therefore exists for a vacuum grip device that is simple, effective, reliable and economical in manufacture and use.